Lycopene is a highly lipophilic procarotenoid present in greatest amounts in the species Lycopersicum although it may be found in lower amounts in other vegetable and algae species. Lycopene is present in common tomatoes in concentrations ranging from 30 to 100 ppm, on the average at 50 ppm. It is usually present as a secondary metabolite in mammals, where it plays an important role as an antioxidant and free-radicals scavenger, together with substances such as Vitamin E, Vitamin C and other compounds. At the plasma level, lycopene has been found to be incorporated in low-density lipoproteins in which it decreases the oxidation of cholesterol and of other lipids, thus preventing vascular damage. Moreover, an inverse correlation between lycopene blood levels and prostate tumor has recently been proved. The administration of lycopene to humans is therefore important in reducing the risk of tumors and atherosclerosis; hence the need for stable formulations containing lycopene for a preventive chronic treatment in humans.